Target of Opportunity Activation

Scheduling ToO Observations

Gemini North and South are accepting triggers for approved
"Target of Opportunity" or ToO programs as described in the Call for Proposals. We
recognize that many ToO programs require follow-up observations on
various timescales. Every effort will be made to complete these
observations but due to schedule (and weather) constraints this cannot
be guaranteed.

ToO Trigger Types:

"Standard" triggers:
observations that, once triggered, can be executed more than 24 hours in the future. This is essentially identical to the
normal queue mode except that the targets are not known in
advance. Thus, observations will be placed in the queue based on
science rank and observing conditions constraints. If you want a
triggered observation to be considered under this mode, you must complete the timing constraints in the
Observing Conditions OT component. The PI will be notified if the
telescope is not available within that time frame, and will be given
the option to change his/her trigger.

"Rapid response"
triggers: observations
that need to be done within the next 24 hours. The minimum
response time is about 20 minutes and these triggers can interrupt
ongoing observations, both classical and queue. Each semester only a few
programs are allocated "Rapid Response" status by the ITAC. Details of
this mechanism are given below. The Gemini
North and South schedules show the science and engineering blocks
available; the schedule is subject to change at short or no notice.
Daily information about instrument availabilities and
configuration can also be found on the
North
and
South
configuration pages. Please
contact your program's Contact Scientist or the Instrument Scientist
if you need more detailed information on the availability of the
telescope during a specific period.

All
types of ToO observations can be prepared and submitted using the
standard sync operations of the Observing Tool (OT). It is also possible to trigger
observations by sending a Uniform Resource Locator (URL) with all the
observation information to secure web sockets on the observing database
machines. Template observations in the programs are copied,
populated with the target and guide star information, and then
triggered.

Phase II Preparation

The
basics of ToO Phase II preparation
are the same as for regular queue programs. However, in this case
the PI needs to define template observations that will be used once the
targets are known. For programs with standard triggers that
require a limited set of instrument modes, PIs should prepare
templates similar to normal Phase II preparation. Programs that
observe more transient objects (e.g. SNe, GRBs) often use many
instrument modes so have to have more triggering options. For
these programs the contact scientist will often copy a set of standard
templates into the program. Please ask your contact scientist for
additional instructions.

Template observations should be made for each
instrument configuration that will be needed and should be stored in a
folder called Templates. This template observations should include:

After being checked by NGO and Gemini
staff, trigger template observations will have their status set to
"On Hold" and the priorities set to the usual High, Medium, or
Low. PIs should sync their
programs and wait for the triggering event.

In
the 2008A OT the ToO observation priority was removed. Each program now
has a ToO status based on the option ("None", "Standard", or "Rapid")
approved during Phase I. The status is given at the main program level.

The
TOO status is also shown at the observation level for programs that are
allowed to trigger TOO observations. Programs with Standard TOO status
can only trigger Standard TOOs while programs with Rapid TOO status can
trigger either kind.

Standard TOO program

Rapid TOO program

Only one
unique template for each configuration should be defined even if
more than one observation with a given configuration may be triggered
on a given night. If the URL-based triggering mechanism
described below is not going to be
used then an Observing Tool "Note" should be used to ask
the Gemini contact scientist to make a number of copies of each
template and leave them all at On Hold.

Triggering an
Observation

Prepare
observation

In most cases these steps are carried
out using the Observing Tool. If URL-triggering is used then much of the preparation is done in software
external to the OT that formats a URL string with all the required
information. Scripts for automatically finding guide stars, formatting
the URL, and submitting it are under development and the PIs for TOO programs can obtain them by contacting Bryan Miller
(bmillergemini.edu).

Submit observation

Change the status of the observations to be triggered from
"On hold" to "Prepared."

Sync the program to the Gemini database.

URL triggering

The PI software sends the URL string to the appropriate web
socket.

Data Collection and Packaging

For Standard triggers the observations will be scheduled at the appropriate time
in the queue. For Rapid Response triggers, the observers are
notified of the triggers immediately and respond according to the
timing instructions given. If the observers have any questions
about the observtion then they may get clarification from the PI
contact given in the note. If the observation cannot be done then
the reasons will be added to the note.

Raw data files usually arrive
at the Gemini Science Archive within a few minutes of being taken and
are accessible by the PIs. For Rapid Response programs the
observer will send an e-mail to the PI contact announcing that data is
available.